Shared parking allows you to put a call on hold from one phone, and then have the call picked up by any other phone in the building.
When a call has been placed on shared park, you will see a red light on one of the buttons on your 3CX phone system.
To answer the call, pick up your phone and press the lit up button.
Alternatively, you can also place a call on shared park yourself.
When you are on a call, simply choose one of the green shared park slots on your phone system. If a slot is green, this indicates that nobody is using that slot.
Press the button beside your chosen slot. You will now see this button light up red.
You will be dropped out of the call, and can hang up.